/*

-Procedure gfrr_c (GF, range rate search )

-Abstract
 
   Determine time intervals for which a specified constraint 
   on the observer-target range rate is met. 
 
-Disclaimer
 
   THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE 
   CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. 
   GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE 
   ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE 
   PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" 
   TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY 
   WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A 
   PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC 
   SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE 
   SOFTWARE AND RELATED MATERIALS, HOWEVER USED. 
 
   IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA 
   BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT 
   LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, 
   INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, 
   REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE 
   REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. 
 
   RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF 
   THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY 
   CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE 
   ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. 
 
-Required_Reading
 
   GF 
   NAIF_IDS 
   SPK 
   TIME 
   WINDOWS   
 
-Keywords
 
   EVENT 
   GEOMETRY 
   EPHEMERIS 
   SEARCH 
   WINDOW 
 
*/

   #include <stdlib.h>
   #include "SpiceUsr.h"
   #include "SpiceGF.h"
   #include "SpiceZfc.h"
   #include "SpiceZmc.h"
   #include "zzalloc.h"
 
   void gfrr_c ( ConstSpiceChar     * target,
                 ConstSpiceChar     * abcorr,
                 ConstSpiceChar     * obsrvr,
                 ConstSpiceChar     * relate,
                 SpiceDouble          refval,
                 SpiceDouble          adjust,
                 SpiceDouble          step,
                 SpiceInt             nintvls,
                 SpiceCell          * cnfine,
                 SpiceCell          * result  )

/*

-Brief_I/O
 
   Variable  I/O  Description 
   --------  ---  -------------------------------------------------- 
   SPICE_GF_CNVTOL   P   Convergence tolerance 
   target            I   Name of the target body. 
   abcorr            I   Aberration correction flag. 
   obsrvr            I   Name of the observing body. 
   relate            I   Relational operator. 
   refval            I   Reference value. 
   adjust            I   Adjustment value for absolute extrema searches. 
   step              I   Step size used for locating extrema and roots. 
   nintvls           I   Workspace window interval count. 
   cnfine           I-O  SPICE window to which the search is confined. 
   result            O   SPICE window containing results. 
 
-Detailed_Input
 
   target      is the name of a target body. The target body is  
               an ephemeris object; its trajectory is given by 
               SPK data. 
 
               The string `target' is case-insensitive, and leading 
               and trailing blanks in `target' are not significant. 
               Optionally, you may supply a string containing the 
               integer ID code for the object. For example both 
               "MOON" and "301" are legitimate strings that indicate 
               the Moon is the target body.  
 
               The target and observer define a position vector which
               points from the observer to the target; the time derivative
               length of this vector is the "range rate" that serves as
               the subject of the search performed by this routine.
 
 
   abcorr      indicates the aberration corrections to be applied to 
               the observer-target state vector to account for 
               one-way light time and stellar aberration. 
 
               Any aberration correction accepted by the SPICE  
               routine spkezr_c is accepted here. See the header 
               of spkezr_c for a detailed description of the  
               aberration correction options. For convenience, 
               the options are listed below: 
 
                  "NONE"     Apply no correction.    
 
                  "LT"       "Reception" case:  correct for 
                             one-way light time using a Newtonian 
                             formulation. 
 
                  "LT+S"     "Reception" case:  correct for 
                             one-way light time and stellar 
                             aberration using a Newtonian 
                             formulation. 
 
                  "CN"       "Reception" case:  converged 
                             Newtonian light time correction. 
 
                  "CN+S"     "Reception" case:  converged 
                             Newtonian light time and stellar 
                             aberration corrections. 
 
                  "XLT"      "Transmission" case:  correct for 
                             one-way light time using a Newtonian 
                             formulation. 
 
                  "XLT+S"    "Transmission" case:  correct for 
                             one-way light time and stellar 
                             aberration using a Newtonian 
                             formulation. 
 
                  "XCN"      "Transmission" case:  converged 
                             Newtonian light time correction. 
 
                  "XCN+S"    "Transmission" case:  converged 
                             Newtonian light time and stellar 
                             aberration corrections. 
 
               Case and blanks are not significant in the string 
               `abcorr'. 
 
   obsrvr      is the name of the observing body. The observing body is
               an ephemeris object; its trajectory is given by SPK
               data. `obsrvr' is case-insensitive, and leading and
               trailing blanks in `obsrvr' are not significant.
               Optionally, you may supply a string containing the
               integer ID code for the object. For example both "MOON"
               and "301" are legitimate strings that indicate the Moon
               is the observer.
 
   relate      is a relational operator used to define a constraint 
               on observer-target range rate. The result window found 
               by this routine indicates the time intervals where 
               the constraint is satisfied. Supported values of 
               `relate' and corresponding meanings are shown below: 
 
                  ">"      Distance is greater than the reference 
                           value `refval'. 
 
                  "="      Distance is equal to the reference 
                           value `refval'. 
 
                  "<"      Distance is less than the reference 
                           value `refval'. 
 
 
                 "ABSMAX"  Distance is at an absolute maximum. 
 
                 "ABSMIN"  Distance is at an absolute  minimum. 
 
                 "LOCMAX"  Distance is at a local maximum. 
 
                 "LOCMIN"  Distance is at a local minimum. 
 
              The caller may indicate that the region of interest 
              is the set of time intervals where the quantity is 
              within a specified distance of an absolute extremum. 
              The argument `adjust' (described below) is used to 
              specify this distance. 
 
              Local extrema are considered to exist only in the 
              interiors of the intervals comprising the confinement 
              window:  a local extremum cannot exist at a boundary 
              point of the confinement window. 
 
              Case is not significant in the string `relate'. 
 
    refval    is the reference value used together with the argument 
              `relate' to define an equality or inequality to be 
              satisfied by the range rate between the specified target 
              and observer. See the discussion of `relate' above for 
              further information. 
 
              The units of `refval' are km/sec. 
 
   adjust     is a parameter used to modify searches for absolute
              extrema: when `relate' is set to "ABSMAX" or "ABSMIN" and
              `adjust' is set to a positive value, gfdist_c will find
              times when the observer-target range rate is within
              `adjust' km/sec of the specified extreme value.
 
              If `adjust' is non-zero and a search for an absolute
              minimum `min' is performed, the result window contains
              time intervals when the observer-target range rate has
              values between `min' and min+adjust.
 
              If the search is for an absolute maximum `max', the
              corresponding range is from max-adjust to `max'.

              `adjust' is not used for searches for local extrema,
              equality or inequality conditions.
 
   step       is the step size to be used in the search. `step' must 
              be short enough for a search using this step size 
              to locate the time intervals where the specified 
              range rate function is monotone increasing or 
              decreasing. However, `step' must not be *too* short, or 
              the search will take an unreasonable amount of time. 
 
              The choice of `step' affects the completeness but not 
              the precision of solutions found by this routine; the 
              precision is controlled by the convergence tolerance. 
              See the discussion of the parameter SPICE_GF_CNVTOL for 
              details. 
 
              `step' has units of TDB seconds.  
 
   nintvls    is a parameter specifying the number of intervals that
              can be accommodated by each of the dynamically allocated
              windows used internally by this routine. `nintvls' should
              be at least as large as the number of intervals within
              the search region on which the specified range rate
              function is monotone increasing or decreasing. See
              the Examples section below for code examples illustrating
              the use of this parameter.

   cnfine     is a SPICE window that confines the time period over 
              which the specified search is conducted. `cnfine' may 
              consist of a single interval or a collection of  
              intervals.  
 
              In some cases the confinement window can be used to 
              greatly reduce the time period that must be searched 
              for the desired solution. See the Particulars section 
              below for further discussion. 
               
              See the Examples section below for a code example  
              that shows how to create a confinement window. 
 
-Detailed_Output
 
   cnfine     is the input confinement window, updated if necessary
              so the control area of its data array indicates the
              window's size and cardinality. The window data are
              unchanged.


   result     is the window of intervals, contained within the
              confinement window `cnfine', on which the specified
              constraint is satisfied.
 
              If `result' is non-empty on input, its contents will be
              discarded before 'gfrr_c' conducts its search.
 
              `result' must be declared with sufficient size to capture
              the full set of time intervals within the search region
              on which the specified constraint is satisfied.
 
              If the search is for local extrema, or for absolute
              extrema with `adjust' set to zero, then normally each
              interval of `result' will be a singleton: the left and
              right endpoints of each interval will be identical.
 
              If no times within the confinement window satisfy the
              constraint, `result' will be returned with a cardinality
              of zero.
 
-Parameters
 
   SPICE_GF_CNVTOL   

              is the convergence tolerance used for finding endpoints
              of the intervals comprising the result window.
              SPICE_GF_CNVTOL is used to determine when binary searches
              for roots should terminate: when a root is bracketed
              within an interval of length SPICE_GF_CNVTOL, the root is
              considered to have been found.
 
              The accuracy, as opposed to precision, of roots found 
              by this routine depends on the accuracy of the input 
              data. In most cases, the accuracy of solutions will be 
              inferior to their precision. 
 
              SPICE_GF_CNVTOL is declared in the header file SpiceGF.h.
 
-Exceptions
 
   1)  In order for this routine to produce correct results, 
       the step size must be appropriate for the problem at hand. 
       Step sizes that are too large may cause this routine to miss 
       roots; step sizes that are too small may cause this routine 
       to run unacceptably slowly and in some cases, find spurious 
       roots. 
 
       This routine does not diagnose invalid step sizes, except 
       that if the step size is non-positive, an error is signaled 
       by a routine in the call tree of this routine. 
 
   2)  Due to numerical errors, in particular, 
 
          - Truncation error in time values 
          - Finite tolerance value 
          - Errors in computed geometric quantities 
 
       it is *normal* for the condition of interest to not always be 
       satisfied near the endpoints of the intervals comprising the 
       result window. 
 
       The result window may need to be contracted slightly by the 
       caller to achieve desired results. The SPICE window routine 
       wncond_c can be used to contract the result window. 
 
   3)  If an error (typically cell overflow) occurs while performing  
       window arithmetic, the error will be diagnosed by a routine 
       in the call tree of this routine. 
 
   4)  If the relational operator `relate' is not recognized, an  
       error is signaled by a routine in the call tree of this 
       routine. 
 
   5)  If the aberration correction specifier contains an
       unrecognized value, an error is signaled by a routine in the
       call tree of this routine.
       
   6)  If 'adjust' is negative, the error SPICE(VALUEOUTOFRANGE) will
       signal from a routine in the call tree of this routine. 

       A non-zero value for 'adjust' when 'relate' has any value other than 
       "ABSMIN" or "ABSMAX" causes the error SPICE(INVALIDVALUE) to
       signal from a routine in the call tree of this routine. 
 
   7)  If either of the input body names do not map to NAIF ID 
       codes, an error is signaled by a routine in the call tree of 
       this routine. 
 
   8)  If required ephemerides or other kernel data are not 
       available, an error is signaled by a routine in the call tree 
       of this routine. 
 
   9)  If the workspace interval count is less than 1, the error
       SPICE(VALUEOUTOFRANGE) will be signaled.

   10) If the required amount of workspace memory cannot be
       allocated, the error SPICE(MALLOCFAILURE) will be
       signaled.

   11) If any input string argument pointer is null, the error
       SPICE(NULLPOINTER) will be signaled.

   12) If any input string argument is empty, the error 
       SPICE(EMPTYSTRING) will be signaled.

   13) If either input cell has type other than SpiceDouble,
       the error SPICE(TYPEMISMATCH) is signaled.
 
-Files
 
   Appropriate kernels must be loaded by the calling program before 
   this routine is called. 
 
   The following data are required: 
 
      - SPK data: ephemeris data for target and observer for the 
        time period defined by the confinement window must be 
        loaded. If aberration corrections are used, the states of 
        target and observer relative to the solar system barycenter 
        must be calculable from the available ephemeris data. 
        Typically ephemeris data are made available by loading one 
        or more SPK files via furnsh_c. 
 
      - If non-inertial reference frames are used by the SPK files, 
        then PCK files, frame kernels, C-kernels, and SCLK kernels may
        be needed.
 
   In all cases, kernel data are normally loaded once per program 
   run, NOT every time this routine is called. 
 
-Particulars

   This routine determines if the caller-specified constraint condition
   on the geometric event (range rate) is satisfied for any time intervals
   within the confinement window 'cnfine'. If one or more such time 
   intervals exist, those intervals are added to the 'result' window.
    
   This routine provides a simpler, but less flexible interface 
   than does the routine gfevnt_c for conducting the searches for
   observer-target range rate value events. Applications that require
   support for progress reporting, interrupt handling, non-default step 
   or refinement functions, or non-default convergence tolerance should
   call gfevnt_c rather than this routine. 
 
   Below we discuss in greater detail aspects of this routine's 
   solution process that are relevant to correct and efficient 
   use of this routine in user applications. 
    
 
   The Search Process 
   ================== 
 
   Regardless of the type of constraint selected by the caller, this
   routine starts the search for solutions by determining the time
   periods, within the confinement window, over which the specified
   range rate function is monotone increasing and monotone decreasing.
   Each of these time periods is represented by a SPICE window. Having
   found these windows, all of the range rate function's local extrema
   within the confinement window are known. Absolute extrema then can
   be found very easily.
 
   Within any interval of these "monotone" windows, there will be at 
   most one solution of any equality constraint. Since the boundary 
   of the solution set for any inequality constraint is the set  
   of points where an equality constraint is met, the solutions of 
   both equality and inequality constraints can be found easily 
   once the monotone windows have been found. 
     
 
   Step Size 
   ========= 
 
   The monotone windows (described above) are found via a two-step 
   search process. Each interval of the confinement window is 
   searched as follows: first, the input step size is used to 
   determine the time separation at which the sign of the rate of 
   change of range rate  will be sampled. Starting at 
   the left endpoint of an interval, samples will be taken at each 
   step. If a change of sign is found, a root has been bracketed; at 
   that point, the time at which the range rate is zero can be 
   found by a refinement process, for example, via binary search. 
 
   Note that the optimal choice of step size depends on the lengths 
   of the intervals over which the range rate function is monotone: 
   the step size should be shorter than the shortest of these 
   intervals (within the confinement window). 
 
   The optimal step size is *not* necessarily related to the lengths 
   of the intervals comprising the result window. For example, if 
   the shortest monotone interval has length 10 days, and if the 
   shortest result window interval has length 5 minutes, a step size 
   of 9.9 days is still adequate to find all of the intervals in the 
   result window. In situations like this, the technique of using 
   monotone windows yields a dramatic efficiency improvement over a 
   state-based search that simply tests at each step whether the 
   specified constraint is satisfied. The latter type of search can 
   miss solution intervals if the step size is shorter than the 
   shortest solution interval. 
 
   Having some knowledge of the relative geometry of the target and 
   observer can be a valuable aid in picking a reasonable step size. 
   In general, the user can compensate for lack of such knowledge by 
   picking a very short step size; the cost is increased computation 
   time. 
 
   Note that the step size is not related to the precision with which 
   the endpoints of the intervals of the result window are computed. 
   That precision level is controlled by the convergence tolerance. 
 
 
   Convergence Tolerance 
   ===================== 
 
   As described above, the root-finding process used by this routine 
   involves first bracketing roots and then using a search process 
   to locate them. "Roots" are either times when local extrema are 
   attained or times when the range rate function is equal to a 
   reference value. All endpoints of the intervals comprising the 
   result window are either endpoints of intervals of the 
   confinement window or roots. 
 
   Once a root has been bracketed, a refinement process is used to 
   narrow down the time interval within which the root must lie. 
   This refinement process terminates when the location of the root 
   has been determined to within an error margin called the 
   "convergence tolerance." The convergence tolerance used by this 
   routine is set via the parameter SPICE_GF_CNVTOL. 
  
   The value of SPICE_GF_CNVTOL is set to a "tight" value so that the 
   tolerance doesn't become the limiting factor in the accuracy of 
   solutions found by this routine. In general the accuracy of input 
   data will be the limiting factor. 
 
   To use a different tolerance value, a lower-level GF routine such 
   as gfevnt_c  must be called. Making the tolerance tighter than 
   SPICE_GF_CNVTOL is unlikely to be useful, since the results are unlikely 
   to be more accurate. Making the tolerance looser will speed up 
   searches somewhat, since a few convergence steps will be omitted. 
   However, in most cases, the step size is likely to have a much 
   greater affect on processing time than would the convergence 
   tolerance. 
 
 
   The Confinement Window 
   ====================== 
 
   The simplest use of the confinement window is to specify a time 
   interval within which a solution is sought. However, the 
   confinement window can, in some cases, be used to make searches 
   more efficient. Sometimes it's possible to do an efficient search 
   to reduce the size of the time period over which a relatively 
   slow search of interest must be performed. 
 
   Consider the following example: suppose one wishes to find the 
   times when the range rate between Io and the Earth attains a global 
   minimum over some (lengthy) time interval. There is one local 
   minimum every few days. The required step size for this search 
   must be smaller than the shortest interval on which the range rate 
   is monotone increasing or decreasing; this step size will be less 
   than half the average time between local minima. However, we know 
   that a global minimum can't occur when the Jupiter-Sun-Earth 
   angle is greater than 90 degrees. We can use a step size of a 
   half year to find the time period, within our original time 
   interval, during which this angle is less than 90 degrees; this 
   time period becomes the confinement window for our Earth-Io 
   range rate search. This way we've used a quick (due to the large 
   step size) search to cut out about half of the search period over 
   which we must perform a slower search using a small step size.  
 
-Examples
 
   The numerical results shown for these examples may differ across 
   platforms. The results depend on the SPICE kernels used as 
   input, the compiler and supporting libraries, and the machine 
   specific arithmetic implementation. 
 
   The examples shown below require a "standard" set of SPICE 
   kernels. We list these kernels in a meta kernel named  
   'standard.tm'. 
    
   #include <stdio.h>
   #include <stdlib.h>
   #include <string.h>

   #include "SpiceUsr.h"

   #define       MAXWIN    20000
   #define       TIMFMT    "YYYY-MON-DD HR:MN:SC.###"
   #define       TIMLEN    41
   #define       NLOOPS    7

   int main( int argc, char **argv )
      {

      /.
      Create the needed windows. Note, one window
      consists of two values, so the total number
      of cell values to allocate is twice
      the number of intervals.
      ./
      SPICEDOUBLE_CELL ( result, 2*MAXWIN );
      SPICEDOUBLE_CELL ( cnfine, 2        );

      SpiceDouble       begtim;
      SpiceDouble       endtim;
      SpiceDouble       step;
      SpiceDouble       adjust;
      SpiceDouble       refval;
      SpiceDouble       beg;
      SpiceDouble       end;

      SpiceChar         begstr [ TIMLEN ];
      SpiceChar         endstr [ TIMLEN ];
      
      SpiceChar       * target = "MOON";         
      SpiceChar       * abcorr = "NONE";
      SpiceChar       * obsrvr = "SUN";
      
      SpiceInt          count;
      SpiceInt          i;
      SpiceInt          j;

      ConstSpiceChar * relate [NLOOPS] = { "=",
                                           "<",
                                           ">",
                                           "LOCMIN",
                                           "ABSMIN",
                                           "LOCMAX",
                                           "ABSMAX",
                                         };

      /.  
      Load kernels.
      ./
      furnsh_c( "standard.tm" );
   
      /.  
      Store the time bounds of our search interval in
      the cnfine confinement window.
      ./
      str2et_c( "2007 JAN 01", &begtim );
      str2et_c( "2007 APR 01", &endtim );
   
      wninsd_c ( begtim, endtim, &cnfine );

      /.  
      Search using a step size of 1 day (in units of seconds).  
      The reference value is .3365 km/s. We're not using the  
      adjustment feature, so we set 'adjust' to zero.
      ./
      step   = spd_c();
      adjust = 0.;
      refval = .3365;

      for ( j = 0;  j < NLOOPS;  j++ )
         {

         printf ( "Relation condition: %s \n",  relate[j] );

         /.  
         Perform the search. The SPICE window 'result' contains 
         the set of times when the condition is met. 
         ./
         gfrr_c ( target,
                  abcorr,
                  obsrvr,
                  relate[j],
                  refval,
                  adjust,
                  step,
                  MAXWIN,
                  &cnfine,
                  &result );

         count = wncard_c( &result );

         /.
         Display the results.
         ./
         if (count == 0 ) 
            {
            printf ( "Result window is empty.\n\n" );
            }
         else
            {
            for ( i = 0;  i < count;  i++ )
               {

               /.
               Fetch the endpoints of the Ith interval
               of the result window.
               ./
               wnfetd_c ( &result, i, &beg, &end );

               timout_c ( beg, TIMFMT, TIMLEN, begstr ); 
               timout_c ( end, TIMFMT, TIMLEN, endstr );

               printf ( "Start time, drdt = %s \n", begstr );
               printf ( "Stop time,  drdt = %s \n", endstr );

               }
               
            }

         printf("\n");
         
         }

      /.
      It's always good form to unload kernels after use,
      particularly in IDL due to data persistence.
      ./
      kclear_c();
      
      return( 0 );
      }
   
 
   The program outputs: 
 
   Relation condition: = 
   Start time, drdt = 2007-JAN-02 00:35:19.574 
   Stop time,  drdt = 2007-JAN-02 00:35:19.574 
   Start time, drdt = 2007-JAN-19 22:04:54.899 
   Stop time,  drdt = 2007-JAN-19 22:04:54.899 
   Start time, drdt = 2007-FEB-01 23:30:13.428 
   Stop time,  drdt = 2007-FEB-01 23:30:13.428 
   Start time, drdt = 2007-FEB-17 11:10:46.540 
   Stop time,  drdt = 2007-FEB-17 11:10:46.540 
   Start time, drdt = 2007-MAR-04 15:50:19.929 
   Stop time,  drdt = 2007-MAR-04 15:50:19.929 
   Start time, drdt = 2007-MAR-18 09:59:05.959 
   Stop time,  drdt = 2007-MAR-18 09:59:05.959 
   
   Relation condition: < 
   Start time, drdt = 2007-JAN-02 00:35:19.574 
   Stop time,  drdt = 2007-JAN-19 22:04:54.899 
   Start time, drdt = 2007-FEB-01 23:30:13.428 
   Stop time,  drdt = 2007-FEB-17 11:10:46.540 
   Start time, drdt = 2007-MAR-04 15:50:19.929 
   Stop time,  drdt = 2007-MAR-18 09:59:05.959 
   
   Relation condition: > 
   Start time, drdt = 2007-JAN-01 00:00:00.000 
   Stop time,  drdt = 2007-JAN-02 00:35:19.574 
   Start time, drdt = 2007-JAN-19 22:04:54.899 
   Stop time,  drdt = 2007-FEB-01 23:30:13.428 
   Start time, drdt = 2007-FEB-17 11:10:46.540 
   Stop time,  drdt = 2007-MAR-04 15:50:19.929 
   Start time, drdt = 2007-MAR-18 09:59:05.959 
   Stop time,  drdt = 2007-APR-01 00:00:00.000 
   
   Relation condition: LOCMIN 
   Start time, drdt = 2007-JAN-11 07:03:58.988 
   Stop time,  drdt = 2007-JAN-11 07:03:58.988 
   Start time, drdt = 2007-FEB-10 06:26:15.439 
   Stop time,  drdt = 2007-FEB-10 06:26:15.439 
   Start time, drdt = 2007-MAR-12 03:28:36.404 
   Stop time,  drdt = 2007-MAR-12 03:28:36.404 
   
   Relation condition: ABSMIN 
   Start time, drdt = 2007-JAN-11 07:03:58.988 
   Stop time,  drdt = 2007-JAN-11 07:03:58.988 
   
   Relation condition: LOCMAX 
   Start time, drdt = 2007-JAN-26 02:27:33.766 
   Stop time,  drdt = 2007-JAN-26 02:27:33.766 
   Start time, drdt = 2007-FEB-24 09:35:07.816 
   Stop time,  drdt = 2007-FEB-24 09:35:07.816 
   Start time, drdt = 2007-MAR-25 17:26:56.150 
   Stop time,  drdt = 2007-MAR-25 17:26:56.150 
   
   Relation condition: ABSMAX 
   Start time, drdt = 2007-MAR-25 17:26:56.150 
   Stop time,  drdt = 2007-MAR-25 17:26:56.150  

-Restrictions
 
   1) The kernel files to be used by this routine must be loaded 
      (normally using the CSPICE routine furnsh_c) before this 
      routine is called. 
 
   2) This routine has the side effect of re-initializing the 
      range rate quantity utility package. Callers may themselves 
      need to re-initialize the range rate quantity utility 
      package after calling this routine. 
 
-Literature_References
 
   None. 
 
-Author_and_Institution
 
   N.J. Bachman   (JPL) 
   E.D. Wright    (JPL) 
 
-Version
 
   -CSPICE Version 1.0.0, 26-AUG-2009 (EDW)

-Index_Entries
 
 GF range rate search 
 
-&
*/

{ /* Begin gfrr_c */

   /*
   Local variables 
   */
   doublereal            * work;

   static SpiceInt         nw = SPICE_GF_NWDIST;
   SpiceInt                nBytes;

   /*
   Participate in error tracing.
   */

   chkin_c ( "gfrr_c" );

   /*
   Make sure cell data types are d.p. 
   */
   CELLTYPECHK2 ( CHK_STANDARD, "gfrr_c", SPICE_DP, cnfine, result );
   
   /* 
   Initialize the input cells if necessary. 
   */
   CELLINIT2 ( cnfine, result );

   /*
   Check the input strings to make sure each pointer is non-null 
   and each string length is non-zero.
   */
   CHKFSTR ( CHK_STANDARD, "gfrr_c", target );
   CHKFSTR ( CHK_STANDARD, "gfrr_c", abcorr );
   CHKFSTR ( CHK_STANDARD, "gfrr_c", obsrvr );
   CHKFSTR ( CHK_STANDARD, "gfrr_c", relate );

   /*
   Check the workspace size; some mallocs have a violent
   dislike for negative allocation amounts. To be safe,
   rule out a count of zero intervals as well.
   */

   if ( nintvls < 1 )
      {
      setmsg_c ( "The specified workspace interval count # was "
                 "less than the minimum allowed value of one (1)." );
      errint_c ( "#",  nintvls                              );
      sigerr_c ( "SPICE(VALUEOUTOFRANGE)"                   );
      chkout_c ( "gfrr_c"                                   );
      return;
      } 

   /*
   Allocate the workspace. 'nintvls' indicates the maximum number of
   intervals returned in 'result'. An interval consists of
   two values.
   */

   nintvls = 2 * nintvls;

   nBytes  = ( nintvls + SPICE_CELL_CTRLSZ ) * nw * sizeof(SpiceDouble);

   work    = (doublereal *) alloc_SpiceMemory( nBytes );

   if ( !work )
      {
      setmsg_c ( "Workspace allocation of # bytes failed due to "
                 "malloc failure"                               );
      errint_c ( "#",  nBytes                                   );
      sigerr_c ( "SPICE(MALLOCFAILED)"                          );
      chkout_c ( "gfrr_c"                                       );
      return;
      }

   /*
   Let the f2'd routine do the work.
   */

   gfrr_( ( char          * ) target, 
          ( char          * ) abcorr, 
          ( char          * ) obsrvr, 
          ( char          * ) relate, 
          ( doublereal    * ) &refval, 
          ( doublereal    * ) &adjust, 
          ( doublereal    * ) &step, 
          ( doublereal    * ) (cnfine->base),
          ( integer       * ) &nintvls, 
          ( integer       * ) &nw, 
          ( doublereal    * ) work,
          ( doublereal    * ) (result->base),
          ( ftnlen          ) strlen(target), 
          ( ftnlen          ) strlen(abcorr),
          ( ftnlen          ) strlen(obsrvr), 
          ( ftnlen          ) strlen(relate) );

   /*
   De-allocate the workspace. 
   */
   free_SpiceMemory( work );

   /*
   Sync the output cell. 
   */
   if ( !failed_c() )
      {
      zzsynccl_c ( F2C, result ) ;
      }

   ALLOC_CHECK;

   chkout_c ( "gfrr_c" );

} /* End gfrr_c */
